Add "-f -" flags to tar BSD implementations of tar use tape device as default file, so "tar xv" would extract files from tape device instead of standard input.
Avoid printf "%s" NULL If the DISPLAY environment variable is unset, the error message tries to print a NULL pointer with %s. Avoid this by checking display for NULL.
Prepend rm arguments with -- in xclip-cutfile (#44) It makes xclip-cutfile more robust since the final rm will not treat any of its arguments as flags. All the arguments passed to rm are going to be treated as file names.
